Lifting-jack.



A. T. RlCHARDSON.

Patented June 15, 1915.

i; E. R D T N E V m WITNESSES.

THE NQRRIS PETERS Cn., PHOTO-LITHO., WASHINGTON. D C.

les

ANDREW' T. RICHARDSON WORKS, OF VERONA,

OF VERONA, PENNSYLVANIA, ASSIGNOR 'IO VERONA TOOL PENNSYLVANIA, A CORPORATION F PENNSYLVANIA.

LIFTING--JACK.

Specification of Letters Patent.`

Patented JT une 15, 1915.

Application led April 15, 1914. Serial No. 832,014.

T0 all whom it may concern.'

Be it known that I, ANDREW T. RICHARD- soN, a citizen of the United States, and resident of Verona, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Lifting-Jacks; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to lifting-jacks.

The object of my invention is to provide a simple and eiiicient form of lifting-jack in which the jack is raised by a step-by-step movement and also lowered in the same manner.

In the accompanying drawing', Figure 1 is a side view partly broken away illustrating the jack and showing the position of the parts when the jack is arranged for lifting a load; Fig. 2 is a like view showing the position of the parts when the jack is arranged forlowering the load; Fig. 3 is a section on the line 3-3 Fig. 1, and Fig. 4 is a perspective view of the pendulum.

The i-rame or stand 2 of the jack has formed therein the bearings 3 for the pin 4 on which the operating lever 5 is mounted. The lower-pawl 6 is pivotally mounted on the inner end of the lever 5. The upperpawl 7 is suspended from the upper end oi' the frame 2, being mounted on theV studs 8. The said pawls are so mounted as to normally fall by gravity toward the lifting-bar 9, and into engagement with the teeth 10 of said lifting-bar. The lifting-bar is inclosed within the frame 2 and said bar is provided with the vertical grooves 9 which engage guide-ribs on the interior of the frame in the ordinary manner.

The weighted pendulum 11 is pivotally mounted on the cam l2 in the side of the frame and at the lower end of said pendulum is the weight 13. A handle 14 on the cam 12 extends outside the frame and by the turning of said handle the cam is operated to throw the pendulum into reversing position. The pendulum has the linger 15, which in the reverse position of said pendulum, is adapted to engage the stud or lug 16 on the upper pawl 7, and said pendulum has cam-face 17 which is adapted to engage the stud or lug 18 on the lower pawl 6 when in reversing position. The weight 13 at the lower end of the pendulum is contained within the frame, and said weight acts to operate the cam-arm automatically when in reversing position.

VIn raising a load with my improved jack,

Y the cam-arm is in the position indicated in F ig. 1, and on raising and handle by-step motion, the lower-pawl raising the lifting-bar, and the upper-pawl falling into position to hold the bar in this raised position until the lower-pawl has engaged another tooth. hen it is desired to reverse and lower the lifting-bar by a step-by-step motion, the handle 14 of the cam 12 is turned and the cam-arm 11 is thrown forward so that its upper finger 15 will engage the stud 16 of the upper-pawl 7 and its cam portion 17 will be in the path of the stud 18 of the lower-pawl 6. Accordingly as the handle 5 is raised the lower-pawl in its descent comes in engagement with the camportion 17 of the cam-arm 11, and said lower-pawl is thrown out of engagement with the tooth of the lifting-bar, while the upper-pawl moves bygravity into engagement with one of the teeth of the liftingbar, the nger of the cam-arm 11 being thrown back to permit of this falling of the upper-pawl into engagement with the teeth of the lifting-bar. This movement of the finger is due to the weight of the load bearing on the lower pawl, and the movement of the stud 18 along the cam portion 17, said stud moving in a downward course, will act to force the iinger back. As this movement of the hand-lever 5 is repeated a like operation takes place and the liftingbar is lowered by a step-by-step movement until the bar is lowered the desired distance.

In case it is desired to release the liftingbar so that it will drop suddenly the camarm 11 is thrown to its normal position, and the lower-pawl is lowered and moved out to engage the notch 20 on the lower end of the upper pawl, whereupon both pawls are held out of engagement with the lifting-bar and said lifting-bar will drop.

What I claim is:

1. In a lifting jack, the combination with a suitable frame, of a toothed lifting bar, an operating lever, a lower pawl pivotally mounted on said operating lever, an upper pawl suspended from said frame, a pendulum mounted in the frame having a weighted portion at the lower end, a finger at the upper end, and a cam portion intermediate lowering the 5, the lifting-bar is raised by a step- CII opes of this patent my be obtained for ve cents each, addressing `tlie y ,Y wasnipgtomn. c.

Weight at its lower end und a linger t'its upper end, and a. cam portion above said cam intermediate said Weight und-.seid in-` 15 p ger, and projeotions Von said upper and lower puvvls adapted to engage the lsaid nger and saidY earn portion respectively.

YIn testimony whereof, I, the said ANDREW T. RICHARDSON,

,Y y `AYNDEW T. RICHARDSON.

Witnesses: Y

Ro'r. D. TOTTEN, JOHN?. WILL.

ommissoixer i of Petents,

have hereunto set my lnand.;V 20 i 

